Empennage structure for aircraft



e -1 ,1930. J.G. Y- NKESE 1,7 1,565

EQPENNAGE STRUCTURE FOR AIRCRAFT Original Filed May 14, 1925 7 She ets-She et 1 Q i 5 k f N I V a :8? (9 I :2 3 R I w N\ a I WITNESSES v i INVENTOR Feb. 18, 1930. J. G. YONKESE 1,747,565

EMPENNAGE STRUCTURE FOR AIRCRAFT Original i e ay 1 1925 7 Sheets-Sheet 2 Feb. '18, 1930. J. G. YONKESE EMPEN NAGE' STRUCTURE FOR AIRCRAFT Original Filed May 14, 1925 7 Sheets-Sheet UmWi WNEN QWN .V ii v 99 mG N INVENTQR WITNESSES Feb. 18, 1230. J. G. YONKESE EMPENNAGE STRUCTURE FOR AIRCRAFT Original Filed May 14/1925 Sheets-sheaf 4 INVENTOR Feb. 18, .1930. J. G. YONKESE I 5 5.

EMPENNAGE STRUCTURE FOR AIRCRAFT Original Filed May 14, 1925 y 'r Sheets-Sheet s WITNESSES INVENTOR Feb. 18, 1930. J. ca. Y ONKESE EMPENNAGE STRUCTURE FOR AIRCRAFT Original Filed M y 1 1925 7 Sheets-Sheet e v WITNESSES INVENTOR Feb. 18, 1930. J. G. YONKESE EMPENNAGE STRUCTURE FOR AIRCRAFT Original Filed ma 14, 1925 '7 Sheets-Sheet 7 INVENTOR Patented Feb. 18, 1930 UNITED STATES JOSEPH G. YONKESE, OF BROOKLYN, NEW YORK EMPENNAGE STRUCTURE FOR AIRCRAFT 1927. Serial No. 195,4s9e.

This application is a division of my pending application, control mechanism for aeroplanes, Serial No. 30,135, filed May 14, 1925. The present application relates primarily to the empenrgage structure for aircraft. 'It is particularly proposed in the present invention to provide an improved empennage of novel construction and arrangement which is adapted to be used on aircrafts having a single or plurality of bodies. It should be kept in mind that my whole invention has particular reference to the empennage used in the larger type of aircraft and the means whereby this empennage is made suitable for guiding the aircraft when alighting or arising from the ground or water.

The aircraft referred to contains a'plu'rality of controlling. elements which include manually operated systems, assisting power operated systems, and automatically operated systems. In order to accomplish the best results of the controls, it is-necessary that all the control wires or cablesextending from the empennage to the control operating mechanisms at the seat of the pilot shall be arranged in such a manner that a minimum of slack or lost motion is attained, since there is considerable deflection of these control wires or cables, due to their extended length.

These cables are connected in a simple manner to the auxiliary movable control surfaces and are run in a straightpractical manner to the control mechanisms, at the control operator seat of the pilot.

The present invention embodies a strong supporting base for the numerous pulleys and roller guides which are employed for permitting the wires or cables to be moved freely. The control wires or cables which are operatively connected to the controls and their associated guiding mechanisms are enclosed within the structural members of the empennage in order to protect them from the elements, such as water, eddies, and at the same time reducing the air resistance -to a minimum. In this connection, it might be stated that. the arrangement of the empennage or tail group which constitutes the present invention was particularly designed for use in connection with my control mechanism for aeroplanes and being so constructed as to cooperate with such a control arrangement associated with an aircraft of such a type.

An important object of the present invenvators can be elevated from the tail end of the aircraft body or bodies in order'to prevent the stabilizers, rudders and elevators from being damaged by the waves in case the aircraft should be forced to alight in a rough sea.

Another important object of the present invention is to provide means whereby the Various control operatingmechanisms and their accessories will be enclosed within the structural members of the empennagein such a manner as to present a smooth stream-lined box-tail construction, thus reducing the air resistance to a minimum.

Another important object of the invention is to provide means whereby the empennage or tail group may assist as a part of the lift.- ing surface as well as a part of thebalancing surface for the aircraft. Another important object of the invention is to provide means whereby the frame. structures or vertical tail supporting members and the horizontal tail planes or stabilizers are unbroken members in order ,to preserve strength, and housing containers for enclos ing the controlling mechanismsf For this reason, the tail planes or stabilizers are made slotted for receiving their vertical supporting members and oscillating the members when operated.

This invention will be best understood from a consideration of the following detailed description in view of the accompany ing drawings forming a part of the specifi cation. Nevertheless, it is to be understood that the invention is not confined to the disclosure, being susceptible of such changes and modifications which shall define no mate-- rial departure from the salient features of the Original application filed May 14, 1925, Serial No. 30,135. .Divided and this application filed May 31,

1 the same,

claims.

Figure 1 is a lon itudinal sideview in elevatlon of an aircra constructed as disclosed in accordance with the principles of my in-- vention,

Figure 2 is a fragmentary view In elevation of the body showing a modified form'of the empennage of the aircraft,

empennage or tail group assembly disclosing the constructional feature arrangements of Figure 5 is a side view of Figure 4,

Figure 6 is another side view showing a modified form of the same,

Figure 7 is a detail plan view of the lower tail plane or stabilizer,

Figure 8 is a side view detail of a vertical tail-supporting member taken along the line 88 of Figure 4 with the righthand side plate removed disclosing the method of enclosing the controlling operating mechanisms ofthe various controlling elements Within the same,

Figure 9 is a detail side view of another vertical supporting member similar to Fig. 8 taken along the line 99 of Fig. 4,

Figure 10 is a detail side view of one of the fore and aft compressionmembers or ribs, showing the method of connecting the elevators at the rear edge of the stabilizers and disclosing the rudder control arrangement,-

- Figure 11 is a fragmentary plan view of Figure 10 showing a pair of compression members spaced in parallel relation and showing the slotted arrangement in the stabilizers and further disclosing the rudder controlling mechanism, 7

Figure 12 is another fragmentary plan view similar to Figure 11 and discloslng the mechanism for controlling the-elevators an the stabilizers adjustable balance,

Figure 13 is a detail plan view showin a portion of .a vertical tail-supporting mem er at the lower stabilizer in the form of two side plates fastened together and withthe fore and aft vertically extended portions cut off, F i ure 14 is a detail view showing more or less t e disposition ofthe mechanism as disclosed in Figure 12 which is housed within the structure shown in Figure 13, and which both Fi res 13 and 14 form a part of Figure 12, igure 15 is a view in perspective disclosing the arrangement of the adjustable stabilizercontrolling mechanism,

Figure 16 is a view in perspective disclosing the location and method of applying the adjustable stabilizer control at the empen na e I i re 17 is a view in perspective disclosing t e elevator control arrangement at the empennage,

Figure 18 is a view in perspective showing more or less diagrammatically the disposition of the arrangement for controlling the elevators, and

Fi ure 19 is a View in perspective disclosing the rudder control arrangement at the empennage.

To explain the invention, shall now proof the empennage or tail group consists of two tail planes 152 and 1.53, usually called stabilizers, arranged one above the other. The two tail planes or stabilizers are supported by a plurality of frame structures 154, 15 i and 154", serving as vertical tail-supporting members. As shown in Figure 4, the member 154 .being the center tail-supporting member and The two tail ends of the bodies are extending from the upper tail plane through the slotted lower tail plane is firmly secured to the transverse member 150 and rigidly connected by means of further braceimembers 155. .154 are the two tail-supporting members next from the center, i. e., intermediate members and rise from each tail end of the bodies 5 extending from the upper tail plane through the slotted lower tail plane to the bodies. The latter members being firmly secured at the tail end of the bodies between two longitudinal plates which form the main constructional members of the bodies, and they are further rigidly connected by lateral brace members 156, and a ainst longitudinal collapsing by means of brace members 157, usually called booms or outrigger. The latter members beingsecured to a more forward portion of the tail end of the bodies between the center longitudinal plates of the bodies. 154: are the two outer tail-supporting mem- "bers extending between the upper and lower tail planes and from thence they bend toward the bodies forming two pairs of brace members 158 connecting the tail end of the two bodies.

Each of the frame structures consists of, metal or wood, formed in a pair of side plates assembled together, consisting preferably of front and rear vertically extended members or struts.- The members or struts being arranged in parallel relation and symmetrical to the two' struts in the other frame form integrally one piece in the vertical and longitudinal frame.

The three frame structures154 .and 15 9- rudder. shafts 207. The frame structures are drawn in two different forms. Figure 5 is drawn in accordance with a preferred form of the invention showing the rudders pivoted behind the rear struts or columns of the frame structures, while Figure 6 is drawn in accordance with a modified form of theinvention showing the rudders pivoted behind the front struts of the frame structure extendi'ng'rearwardly between the front and the rear struts of the frame structures. The two frame structures 154 are in the line of symmetry with the aircraft bodies and are secured at the tail end of the bodies. These are the two vertical tail-supporting members within which the control operating mechanism of the empennage is enclosed.

The two horizontal tail planes or stabilizers 152 and 153 areslotted at equal intervals and two different places for receiving their vertical supporting members and the elevator control members. The tail planes or stabilizers consist ordinarily of two trans Versal members or spars 152 and 152", and 153 and 153". These members or spars form the front and rear main supporting members for the two tail planes, and are rigidly connected by a plurality of double compressionmeans of internal braces 153.

The members 1539-extend in a fore and aft direction and symmetrical to the members 152 and 152 153 and 153". The former members bein so connected to the latter members as to form between their inner faces a slot or recess opening between front and rear transversal members for receiving the vertical supporting members 154, 154 and 154*, and a slot or recess opening behind the rear transversal members for receiving the upper and lower elevator control members 190 and 191 res ectively, all of identical construction and 0 which five of each are shown (see Fig. 17). The 'members 153 are con-- structed and reinforced for resisting the supporting stresses as follows:

Referring to Figures 7-12 inclusive, it will be seen that adjacent the rear spars 152 and 153*, the members 153 carry the supporting base 160 and 160 for receiving the pivots 161 which connect the tail planes to their vertical supporting members 154, 154 and 154?. Ad-

jacent the front spar 153 they carry the sup- 165 which is employed for raising or lowering the front end of the tail planes. At the rear end, they carry the supporting bases 140 which project further rearwardly from the rear edge of the tail planes for receiving the elevatorcontrol shafts 192 and 193.

Between the inner faces of each double member and behind the rear spars of the two tail planes, they form a slot or recess opening 159 for the oscillation of the elevator control memberslQO and 191. The supportingnumerous ribs 153, and by of facilitating the work of attaching the elevators to the'tail planes or stabilizers, and

' base 140 being made to open for the purpose a they consist of two half portions as folloWs:-.

A-lower portions ofthe. members 153. The upper half 140 is detachable, but may be firmly locked to the lower member by means of a link 141, which extends under a lip 142, through a slot 143 provided-for receivin the link 141. A bolt 144 is .provided for 100 'ng the forward end of 140 to the lower solid half 140 is fixed solid to'the rear,

portion 140. This may be seen more distinctly in Figure 10 which shows the two portions in detached relation.

The two tail planes or stabilizers are pivoted at their rear ends to their respective tail supporting members 154, 154 and 154" inclusive, as shown at 160 and 160. Their front ends being arranged to be raised and lowered as adjustable tail planes for the purpose ofthe adjustable balance of the'aircraft are interconnected by means of a plurality of spacing members or links 162 so that the upper plane will follow. the motions of the lower one. The latter plane is swung on its pivots 161 by means of a plurality of pinions 163 located within the hollow portion of the vertical tail supporting members and engaging with a plurality of stationary toothed racks 164 secured to the inner walls of said supportingmembers. The racks are arched to correspond to the periphery of a circle of which the pivots 161 are the center. The pinions 163 are supported on a shaft 165 which is mounted for rotation within the front end of the lower stabilizer 153, as shown in Figures 7 ,and 10-16 inclusive. The pinions are keyed or otherwise secured to the shaft so as to rotate with the same and be operated by the same.

The shaft referred to is passed through the arcuately shaped slots 166 formed in the tail supporting members 154, 154 and 154 inclusive, which latter slots are adap'ted to allow the shaft to ride up and down in them during its operation. The shaft being rotated by sprockets 167 located within the'hollow supporting members 154 keyed or formed integrally withthe pinions 163 are adapted to rotate the shaft. The sprockets 167 being operated by means of chain 167 and the second sprockets 168 rotatably mounted on pivots 161 of stabilizer 163but located within the rear end hollow portion of the members 154? and in alignment with the first sprockets.

Sprockets 168 are fixed to or formed -integrally with a pulley member 169 provided for rotating thev latter sprocket, and over which is wound a pair of continuous flexible wires 170-and 17 0 secured at their middle portions to the pulley, one end of each wire is looped a couple of times clockwise around the pulley,

while the other end is looped a couple of times counter-clockwise around the same pulley, in order allow the pulley to turn either way to cause the pinions 163 to ride up or down on racks 164.

The two pairs of wires leading from their respective pulleys 169 and each pair forming four ends, are brought downwardly and passed over sheaves or pulley member 171. The two ends of wire 17 0 of both the right andv the left hand side are carried straight. for

ward to drums 172 and 173 located ,in'the pilots seat in each of the air Icraft bodies 5 provided for operating the wires. The wires are wound around the drums as follows The end of wire 170 whichis wonnd clockwise around the pulleys 169 is wound also a couple of times clockwise around the drums and secured thereto, and the end of wire 170 which is wound counter-clockwise'around the pulleys 169 is wound, also a couple of times counterclockwise aroundff' the drums and secured thereto. The gwires referred to are' wound clockwise and counter-clockwise around their respective pulleys, in "order to allow both the drums and pulleys to rotate at least one or twice in either direction so as to allow the required" amountof rotation sufficient to operate shaft 165 without causing thelatter-wires to come to an end during this control operatlon.

: Wires 1'70 are similar to employed for the purpose of connecting the n on es on theleft hand side, and the left hand sidecontrol to cooperate with the ones on the right-hand side; so that this control may be operated from either the drum 17 2 or 17 3,

' from either one of the aircraft bodies 5, and

whenever one of the drumsis operated, will control both p irs of sprockets 168 in order to e ualize th strain of theshaft 165' and avoi ing the twisting stress" of the same, The latter wires are erected as follows: The end I of 'wire 70 which is wound clockwise on the left pulley 169 is passed-over sheaves 174 and over sheaves 17 5 and connected with the end of. wire which is wound clockwise on' the right pulley 69 as shown at 176, while the end ofwire 17 0 which is wound clockwise on the right pulley 169 is passed over sheaves 175 and oyer sheaves 174 and connected with the end of wire 170 which is wound clockwise on the left pulley 169, as shown at 177. The end of wire 170 which is wound counter-clockwise on the-left pulley 169 is passed over. sheave {174 and sheaves 175 and connected the end of wire 170 which is wound counterclockwise on the right pulley. 169'," as shown fiat 17 8, while the end of wirej170 which is on the left pulley 169 as shown at 179.

wound counter-clockwise on the right pulley 169' is passed over sheaves 17 5 and over sheaves 174 and connected with the end of wire 170 which is wound counter-clockwise Both the drums 172 and 17 3 are provided with a worm gear 180 and 181 operated by be maintained at the thand side control to cooperate with the worms 182 and 183 on a crank 184 and 185. The drums are arranged in the pilot control operating seat so thatthe cranks 184 and 185 can be conveniently reached by the pilot when he desires'to regulate the nose or tail heaviness of the aircraft while in the air. Means are provided between the two drums, whereby when either one of them is engaged to operate, the other is released to rotate, and-the ones which may be engaged for operation will worm gear, so the angle of the stabilizermay position desired by the pilot; 4

' Elevators Generally the elevator or elevators and their controlling arrangements of an aircraft are equipped with usually called elevator control horns orother associated members for I controlling the same. In my arrangement, I

provide the elevators 188 and 189. equipped with aseries of elevator control pulleys 190 and 191 coaxially mounted on elevator control shaft 192 and 193 keyed or otherwise secured to theshafts, so as to move with the same and be controlled by the same. The 170, and they arev jecting on the upper and lower surfaces of at "the same time be maintained against rota- 'tion automatically locked by means of the gearing ratio of theworm engaged with the the elevators, with their forward ends made i 7 round to conform with the curvature sha e of the pulleys 190 and 191 of which the sha tsi 192 and 193 are the'center pivots, and with their rear ends vanishing to a cone-shape at the trailing edge of the elevators.

A shaft 193 which carries a series of pul-v leys 191 coaxially mounted thereon and rigidly formed to'the shaft and the frame construction of theelevator 189. is the operating shaft for controlling theelevators. The,

. shaft 192 which carries a series of pulleys I90 coaxially mountedthereon and rigidly fixed. to the shaft and the frame construction of the elevator .188 is an idling shaft, and is connected with the former shaft, so as to move with the same and be carried by the same whenever the latter is. operated, by means of a giljurality of continuous flexible bands 194; .ach of the bands is passed around each corresponding upper and lower pulley 190and 191, as disclosed in Figure 17, and secured to the pulleys, as shown at 190 and 191 are thin streamlined fins outside disposed pro- P Figure 8. The bands referred to may be di vided into two sections and connected together by means of adjustable turnbuckles in order to regulate the correct tensionof the same and the alignment of the elevators.

Both the operating shaft 193 and the idling shaft 192 are rackably mounted in bearings '159 secured to the supporting bases 140 and 191 may be made to 0 en in order to,

facilitate the assembling of t e same in their I bases, and are provided with a slot for the purpose of oscillating the rear spar beam 152 and 153 of the stabilizers during the controlling of the elevators. Referring to the pulleys 190 and 191 which are employed for controlling the elevators and the brace wires for bracing the trailing edge of the elevators, it will be seen that these can be omitted altogether, and in substitution therefor, cone-shaped compression members may be utilized which will serve to reinforce the structure of the elevators, to brace the trailing edge of the same, and for controlling the same. At the difierent stations through the empennage where the rudders are attached to the rear edge of the vertical tailsupporting members, the compression members referred to may project outside on the upper surface of the-upper elevator, and the under surface'of the lower elevator only. At the under surface of the upper elevator and the upper surface of the lower elevator, the compression members may be mutilated in order to clear the way for the rudders right and left swinging as shown in Figure 9. The foremost portionor horns 190 and 191? of the upper and lower members may be connected so as to move both in unison, by m ans of an extension 191 which is enclosed within the rear housing portion of the vertical tail-supporting members. 1

Referring to Figure 18 which is a view in perspective showing more or less diagrammatically the disposition of the connections and relation of the control wires or cables for controlling the elevators at the empennage, it will be seen that this structure is located within the housing container of the vertical tail-supporting members -15l154l which are in the line of symmetry with the aircraft bodies 5. It will be seen therefore, that the elevator control operating shaft 193 has a plurality of grooved pulleys 196 and 197 which are rigidly secured to the shaft or formed integral with pulleys 191 which are also secured to the same shaft. The pulleys 196 and 197 are adapted to receive the main 7, which illustrates one of the, tailor stabilizers, with the elevator in de- Cables 12 and 13 and 12 and 13? are continuous bands which may be divided in sections connected, together by means of adjustable turnbuckles for regulating their correct tension, and they are secured at their center pulling point to pulleys 196 and 197, at the empennage, and to the rear pulley 7 of the general control operatingmeans at the pilots seat. The cables designated as 12 and 13 leading from pulley 196, the end 13 is passed over sheave 198 and the end 12 is passed over sheave 199, then both the ends 12 and' 13 are brought downwardly and passed under elevator control cables 12 and 13, and 12 and i sheaves 200, and from thence brought through the aircraft body or bodies 5 and fastened to pulley 7 as previously stated. The cables designated as 12 a and 13 leading from pulley 197 are similar to the former cables except that the two ends of the right hand side are brought downwardly under sheaves 201, then toward the left over sheaves 202 and connectting the end 12 Wit the 12 and the 13 with the 13 of the left hand side. Likewise, the

- 12 and 13, the left hand side are passed under sheaves 203, over sheaves 204 and conne'cted with the 12 and 13 of the right hand side.

Both the 12*- and 13 are so connected with 12 nd 13 that a pull exercised on either of main cables 12 will cause both the right and left operating pulleys 191 to move clockwise and through the medium of the connec tion of bands 19 1 will cause both the upper and lower elevators to incline upwardly, while a pull exercised on either main cable'13 will cause both the operating pulleys 191t0 move counter-clockwise and lowering the ele- I yators downwardly. The air craftlmay be steered in a vertical plane bodies 5, and at the same time equalizing the strain on the operating shaft 193 and avoiding the twisting stresses of the same.

Referring to the tail planes or stabilizers, it should be understood that the same are not necessarily pivoted in the rear struts orcolu'mns of the tail supporting members, but

. may also be pivoted in the front struts of the same, in which latter case the rear end of the stabilizers may swing about the front ivots by means of an arrangement similar to t at of pinions 163 and racks 164 arranged in the opposite way. required in the case where the rudders are pivoted as shown in Figure 19. In such case, the

from either one of R The latter arrangement would be a spacing members or links 162 may be formed I at the rear ends of the stabilizers as shown in Figure 6 instead ofbeing at the front end.

Rudder-s The rudders 205 consist of a frame con,-

' struction having 'a series of compression brace members 206 similar in construction to that of the ailerons and that of the elevators. The

. members'referred to are substituted for the usual rudder control horns and rudder brace wlres, and they serve as a horn and brace wires'both. The latter members are formed rigid with the frame construction of the rudders projecting equally oneither side of the same in a flat horizontal position. They form a thin streamlined fin with their forward ends conformin to the curvature of a pulley shape and with t eir rear ends vanishing to a cone shape at the trailing edge of the rudders. Both the rudders 205 and the members 206,

being formed rigid to the rudder shafts 207 so as to move with the latter and be operated by the same in the case of therudders no pulleys are required in the forward ends of the members 206, unless otherwise desired.

The series of rudder control shafts 207 have at their bottom ends, a quadrant member 208 firmly secured to the shafts so that the shafts are turned within the required. angle by means of those quadrants. The quadrants being formed within the lower stabilizer and they ride through slots provided in the fore and aft members 153 of the stabilizer, as

' shown in Figures 10 and 11. A pair of continuous rudder control wires 209 is passed over. the grooves of the series of quadrants, and secured thereto, as shown at 210. The wires referred to being divided in sections and connected by meansof'adjustable turnsideaircraft body 5. The two ends of the were erected'towa'rd the left with one end;

buckles in order to regulate the tension of the same and the spaced alignment of the rudders, are passed over pulleys 211 located with the ends of the rightand left hand sides of the lower stabilizer, and from thence are carried toward the center. The ends of the wire lead from the right, one of which is passed over pulley 212 and over further pulley .213 and then downwardly under pul-' -1ey214 and connected with the main rudder control cable 55 of the jri ht handside airv craft body 5. The other on continues t ward the left passing over the left pulley 21 a and over further pulley 213, then downwardly overpulleys 214" and connected with the main rudder control cable-55 of the left hand wire 209 leading from the left hand side are erected in ,the'opposite direction toward the right in'a similar manner as the former ones passed over a second pulley 212 and over a further second pulley 213, then downwardly under a second -pulley 214% and connected with the main rudder control cable 56 of'the left hand side of the aircraft body, 5, the other end of the wire continues toward the right and passes over a second pulley 212, 213 and 114 and is connected withthe' main rudder control cable 56 of the right hand side aircraft body 5. It should be understood that a "pull exercised on cable 55 from either one of the aircraft bodies will pull on the right hand side ends of the rudder control Wire'209 turnby said stabilizers are cause the sta the stabilizers, means for simultaneously ac-' I ing the rudder to the left, thereby causing for part of the verticaltail supporting members and brace elements of the empennage, and particularly provides housing containers for the crossing control cables of the empennage which pass through this member between the tail end of the twobodies 5. At the same time it is so set in an angle as to give an upward lift, thus assisting to carry the load of the aircraft while in fl1ght.- The member referred to does trolling element.

Iclaimz. 1. An empennage for, aircraft having a main frame-supporting structure, a horizontal bracing member carried by said support not take part as co -I ture and said bracing members, sta ilizer'sfv p llymountedupon the verticalmembers,

ing structure, a lurality of vertical members rigidly molmte upon'said'supportin struc means arranged to oscillate one of said stabi lizers, a plurality of links operatively con-- necting the stabilizers, and means foractu ating the stabilizer oscillatin means, whe're to oscillatessr multaneously.

2. An empennage for aircraft having a main frame-supportingstructure a horizon.-

tal bracing member carried by .saidsuppbrt mg structure, a plurality of vertical members rigidly mounted upon said supporting, struc-- ture and said bracing member, stabilizers'piv otally mounted upon the vertical members, means arranged to oscillate one of said stabilizers, a plurality of links operativelyconnecting the stabilizers, means for actuating the stabilizers, elevators pivotally mounted for simultane-g} 3. An empennage for aircraft having a 3 to the stabilizers,;and means ously actuating the elevators.

main frame-supporting structure,.-a horizon-' 7 tal bracing member carried by said supporting structure,a lurality of vertical members rigidly mount upon said supporting structure and said bracing member, stabilizers pivotally mounted upon the vertical members, means arranged to oscillate one of said stabilizers, a plurality of links operatively connectin the stabillzers, means for actuating ilizers, elevators pivotally mounted to tuating said elevators, rudders pivotally carried by said vertical members, and means for simultaneously operating said rudders.

at. An empennage structure for aircraft unbroken members, controlling means, and

means for enclosing the controlling means within the structural members of the empennage.

I 5. An empennage structure for aircraft, comprising a box tail assembly, said assembly comprising horizontal unbroken members, vertical unbroken members, bracing elements, means for causingthe horizo'ntal unbroken members to oscillate relative to the vertical unbrc ren members, controlling elements, and means for enclosing the controlling elements within the structural members of the empen-' nage, the means for causing'the horizontal members to oscillate relative to the vertical members comprising a plurality of slots in the horizontal members, and the means for V enclosing the controlling elements within the Cal structural members comprising housing containers provided in the horizontal and vertical members.

6. An empennage structure for aircraft comprising a plurality of assembling means, said assembling means comprising a transversal brace member for bracing the two tail ends of the aircraft bodies, a plurality of frame structures forming vertical tail supporting members of the empennage, a plurality of vertical rudders pivoted on the vertical members, a plurality of horizontal members comprising stabilizers and elevators, bracing elements between said transversal member, the vertical members and the horizontal members forming a rigid stability between the two t'ail ends of the aircraft bodies, adjustable balance mechanism, means for controlling the mechanism, and means for controlling the elevators and rudders.

7. An empennage structure for aircraft, comprising in combination a plurality of frame structures rigidly supported by the tail end of the aircraft body forming the vertical supporting members of the empennage, unbroken stabilizers provided with slots to receive the frame structures, means for pivotally connecting the stabilizers along one edge to the frame structures. means for elevating or lowering the freeedge of the stabilizers, whereby said stabilizers are oscillated on their pivotal connections on said frame structures, said stabilizers being provided with projections on their rear edges forming supporting bearings for receiving the elevator control shafts, a slot or recess being provided between the projections for receiving theelevator control members, and means for operating said elevators.

8. In anempennage for aircraft having stabilizers pivotally mounted, and elevators pivotally carriedby the stabilizers, an operating shaft mounted for. oscillation at the .rear edge of one of said stabilizers, an idling shaft mounted for oscillation at the rear edge of the other stabilizer, both the operating shaft and the idling shaft having a plurality of pulleys coaxially mounted and rigidly secured to said shafts arid the frame construction of the elevators, flexible connection be-l tween each corresponding upper and lower pu leys for causing both shafts to move in unisonwhen said operating shaft is operated, flexible connection between the operating shaft and the control operating mechanism located at the pilotcontrol operating seat,

the latter flexible means being'arranged to operate the latter shaft for controlling the elevators at the empennage.

9. In an empennage for aircraft having stabilizers pivotallymounted one above the other and elevators pivotally mounted to each of said stabilizers, an operating mechanism for said elevators, comprising an'operating shaft and an idling shaft, the operating shaft being mounted for rocking movement at the rear edge of the lower stabilizer, the idling shaft being mounted for rocking movement at the rear edge of the upper stabilizer,'projecting means provided at the rear edge of the upper and lower stabilizers for the supporting of the shafts, each of said shafts having aplurality of compression brace members coaxially-mounted and rigidly formed with said shafts and the frame construction of the,ele-

vators so as to move with the shafts and be ,controlled by the same, the compression brace members projecting evenly on the upper and lower surfaces of the elevators with their front end conforming to the curvature of a pulley and the'rear end to a cone-shaped-member, extension means connecting each corre-' sponding upper and lower member so as to cause the upper and lower shafts to move in unison whenever one of them is operated, and flexible means for controlling the operating shaft.

frame structures rigidly supported by the tail end of the aircraft body or bodies, stabilize'rs provided with slots to receive the frame structures, means for connecting the stabi- 0. An empennage structure for aircraft,

lizers for oscillation to one edge of the frame meeting thestabilizers along one edge to the frame structures, means forelevating or lowering the-free edge of the stabilizers whereby said stabilizers are oscillated'on their pivotal connections on said frame structures, said stabilizers being provided with projections at their rear edges formed with bearings, elevatorspivotally mounted in the bearings,and

means for operating the elevators, said elevators adjacent their pivotal connection with the stabilizers being provided with pulleys rigidly connected therewith, the stabilizers being provided with recesses to receive the outer portions of the pulley.

12.- An empennage structure for aircraft comprising a rigid connection for mounting the empennage on the body'or bodies of the aircraft, frame structures made rigid with the connection and stabilizers pivotally mounted on'the'frame structures, said frame structures bomprisinga pair of plates having openings through the walls thereof and provided with recesses on their inner faces, means for rigidly connecting the plates together in order to form a chamber between the plates by the cooperating recesses. and means for oscillating the freeedges of the stabilizers,

said means being located in the chamber between the plates forming the frame structures. v 4 r 13. An empennage structure for aircraft,

comprising a rigid connection for mounting adjacent the vracks, a shaft mounted in the slots and carried by the free edge of the stabilizers, a gear on the shaft adjacent each rack and in mesh with the rack whereby when the shaft is rotated said shaft, gears and free end of a stabilizer being moved upwardly or downwardly, the gears being likewise d18- posedwithin thechamber between the plates forming said-frame structure.

14. 'An empennagestructure frame structures rigidly supported by the tail end of the aircraft body, stabilizers provided with slots to receive the frame structures,

means for pivotally connecting the stabilizers along one edge to the frame structures, means for elevating or lowering the 'free edge of the stabilizers whereby said stabilizers are oscillated on their hinged connections on the frame structures, said stabilizers being provided with projections attheir rear edges formed with bearings, elevators pivotally for aircraft,

' mounted in the bearings, and means for operating the elevators, said'frame structures being provided with 'elongated openings at points between the stabilizers, and rudders pivotally mountedon the framestructures and disposed within the openings' 7 i 15. An empennage for aircraft having a pair of bodies, frame structures rigidly supported by the tail end of said bodies of the aircraft, stabilizers provided with slots to receive the frame structures, means for pivotally connecting the stabilizers along one edge to the frame structures, means for, elevating or lowering the stabilizers whereby said stabilizers are osdillated on their hinged connections secured to said frame structures, said stabilizers being provided with projections at their rear edges formed with bearings, elevators pivotally mounted in the bearings, and

means for operating the elevators, said elevators adjacent their pivotalconnections with the stabilizers being provided with rearwardly projecting horns, a link connecting the horns of the s aced-apart elevators, and means for operatlng one of said elevators.

16. An empennage for aircraft having a pair of bodies, frame structures rigidly supported by the tail end of said bodies of the aircraft. stabilizers provided with slots to receive the frame structures, means for pivotally connecting the stabilizers along one edge to the frame structures, means for elevating or lowering "the stabilizers whereby said stabilizers are oscillated on their hinged connections carried. by the frame structures, said .stabilizers'being provided with projections at their rear edges formed with bearings, elevators pivotally mounted in the bearings, and means for operating the elevators, said elevators adjacent their pivotal connection with the stabilizers being provided with rearwardly projecting horns, a link connecting the horns of said spaced-apart elevators, and

means for operating. one of the elevators, said frame structures being provided with recesses to accommodatesaid horns,

17. An empennage for aircraft having a pair of bodies,frame structures rigidly supported by the tail end of the bodies of the aircraft, stabilizers provided with slots to receive the frame structures, means for pivotto the frames'tructures, means for elevating or lowering the stabilizers whereby said stabilizers are oscillated on their hinged connections on said frame 'structures, -said stabilizers being provided with projections at their rear edges formed with bearings, elevators pivotally mounted in saidbearings, means for operating said elevators, said elevators adjacent their pivotal connection with the stabilizers being provided with rearwardly projecting horns, a link connecting the horns, means for operating one of the elevators, said frame structures being. provided with rep ally connecting the stabilizers along one edge cesses to accommodate the horns, rudders hingedly mounted on the framestructuresand located between said elevators, the upper and lower ends of the rudders being sheared off at an angle whereby the elevators may be moved towards each other and forming an acute an le with each other when engaged byvthe ad jacent free edge of the rudders; 4 18. An empennage for aircraft having a pair of bodies, frame structures rigidly supported by the tail end of the bodies of said aircraft, stabilizers provided with slots to receive the frame members, means for pivotally connecting the stabilizers along one edge 1 to the framestructureameans for elevating or lowering the stabilizers whereby said stabilizers are oscillated on their hinged con nections on the frame structures, said stabiliz ers being provided with projections at their rear edges formed with bearings, elevators pivotally mounted in the bearings, means for operating the elevators, said frame structures being provided with openings, and rudders located within the openings and pivotally connected with the frame structures, the portions of the frame structures at the periphery of the openings forming a housing for completely enclosing the rudders.

19. An empennage for aircraft having a pair of bodies, frame structures rigidly supported by the tail end 'of the body of the aircraft, stabilizers provided with slots to receive the frame structures, means for pivot- V ally connecting the stabilizers along oneedge to the frame structures, means for elevating.-

or lowering the stabilizers whereby said stabilizers are oscillated on the hinged connections mounted upon said frame structures, said stabilizers-being provided with rojections at their rear edges formed with earings, elevators pivotally mounted in the bearings, and means for operating the eleva-v tors, shafts vertically mounted in the frame structures, said frame structures being provided with openings adjacent the shafts, a rudder rigidly connected with each shaft, a segmental member rigidly. secured to each of the shafts, cables connected to the segmental members and directed oppositely from each other so that when either of the cables are drawn the segmental member will be 'oscil-' lated for rotating the shaft and for oscillat ing the rudders. L 55 JOSEPH G. YONKESEV 

